package Leetcode;

import java.util.*;

/**
 * @ Author     ：侯耀祖
 * @ Description：
 */
public class threeSum {
    public List<List<Integer>> threeSum(int[] nums) {
        List<List<Integer>> result = new ArrayList<>();
        Arrays.sort(nums);
        for (int i = 0; i < nums.length; i++) {
            if (nums[i] > 0){
                return result;
            }
            if (i > 0 && nums[i] == nums[i - 1]){
                continue;
            }
            int left = i + 1;
            int right = nums.length - 1;
            while (left < right){
                if (nums[i] + nums[left] + nums[right] > 0){
                    right--;
                } else if (nums[i] + nums[left] + nums[right] < 0){
                    left++;
                } else {
                    result.add(new ArrayList<>(Arrays.asList(nums[i], nums[left], nums[right])));
                    while (left < right && nums[right] == nums[right - 1]){
                        right--;
                    }
                    while (left < right && nums[left] == nums[left + 1]){
                        left++;
                    }
                    left++;
                    right--;
                }
            }
        }
        return result;
    }
}
